This new paper shows what appears to be a link between Forbush descreases and terrestrial temperature change shortly afterwards. It is a short time scale demonstration of what Svensmark is positing happens on a longer climate appropriate time scale as the solar magnetic field changes with long periods. I’ve covered the topic of Forbush decreases before, and thus I’ll draw on that for a refresher.
A Forbush decrease is a rapid decrease in the observed galactic cosmic ray intensity following a coronal mass ejection (CME). It occurs due to the magnetic field of the plasma solar wind sweeping some of the galactic cosmic rays away from Earth.
Well we have that going on in a dramatic way right now [Feb 19th, 2011], it’s been going on since late yesterday. See the Oulu neutron monitor (a proxy for cosmic rays) graph:
You can monitor it live on the WUWT solar page here.
Nigel Calder reports of a new peer reviewed paper from the Institute of Physics in Belgrade, Serbia which demonstrates a link between such Forbush events and the increase in the diurnal temperature range averaged across 184 stations in Europe. It is quite compelling to read.
Europe: diurnal temperatures after Forbush decreases
A. Dragić, I. Aničin, R. Banjanac, V. Udovičić, D. Joković´, D. Maletić and J. Puzović, “Forbush decreases – clouds relation in the neutron monitor era”, Astrophysics and Space Sciences Transactions, 7, 315–318, 2011.
It was published on 31 August and the full text is available here http://www.astrophys-space-sci-trans.net/7/315/2011/astra-7-315-2011.pdf It’s typical of the pathetic state of science reporting that I still seem to have the story to myself ten days later.
The focus was on the “natural experiments” in which big puffs of gas from the Sun block some of the cosmic rays coming from the Galaxy towards the Earth. The resulting falls in cosmic ray influx, called Forbush decreases, last for a few days. The game is to look for observable reductions in cloudiness in the aftermath of these events. The results are most clearly favourable to the Svensmark hypothesis for the Forbush decreases with the largest percentage reductions in cosmic rays. Scientists keen to falsify the hypothesis have only to mix in some of the weaker events for the untidiness of the world’s weather to “hide the decline”.
The Serbs avoid that blunder by picking out the strongest Forbush decreases. And by using the simple, reliable and long-provided weather-station measurements of temperature by night and day, they avoid technical, interpretive and data-availability problems that surround more direct observations of clouds and their detailed properties. The temperatures come from 184 stations scattered all across Europe (actually, so I notice, from Greenland to Siberia). A compilation by the Mount Washington Observatory that spans four decades, from 1954 to 1995, supplies the catalogue of Forbush decreases.
The prime results are seen here in Dragić et al.‘s Figure 5. The graphs show the increase in the diurnal temperature range averaged across the continent in the days following the onset of cosmic ray decreases (day 0 on the horizontal scales). The upper panel is the result for 22 Forbush events in the range 7−10%, with a peak at roughly +0.35 oC in the diurnal temperature range. The lower panel is for 13 events greater than 10%. The peak goes to +0.6 oC and the influence lasts longer. It’s very satisfactory for the Svensmark hypothesis that the effect increases like this, with greater reductions in the cosmic rays. The results become hard (impossible?) to explain by any mechanism except an influence of cosmic rays on cloud formation.
To be candid, these results are much better than I’d have expected for observations from a densely populated continent with complex weather patterns, where air pollution and effects of vegetation confuse the picture of available cloud condensation nuclei. Svensmark’s team has emphasised the observable effects over the oceans. Now the approach taken by the Belgrade team opens the door to similar investigations in other continents. Let a march around the world’s land masses begin!
Physicist Luboš Motl also writes about the new paper:
What have they found? If they take all Forbush decreases, the effect is insignificant. However, if they compute the average of the largest Forbush decreases, they find a substantial increase of the day-night temperature difference by as much as a Fahrenheit degree around 3 days after the event [reference to Figure 5 above].
…
A higher day-night temperature difference indicates that the number of clouds is smaller – because clouds cool the days but heat up the nights a little bit, and thus reduce the temperature difference – which is in agreement with the cosmoclimatological expectation: the Forbush decreases makes the galactic cosmic rays disappear for some time (because of some massive, temporarily elevated activity of the Sun).
I think it’s both simple and clever to look at the day-night differences because the overall noise in the temperature is suppressed while the signal caused by the clouds is kept. Just to be sure, it’s obvious that clouds do reduce the day-time differences but that doesn’t mean that they preserve the day-night average. At typical places, they cool the days more than they heat up the nights.
For me, this paper begs replication and confirmation. The problem they have with the European data set is that it is noisy which required the averaging. Here in the USA though, there’s a dataset that may work even better, and that’s from the recently completed U.S. Climate Reference Network operated by the National Climatic Data Center. While that network is too new to be useful yet for long term climate studies, the care that was taken for station siting placement, accuracy of sensors, data resolution, and quality control make it a perfect candidate for use in replication of this effect.
These stations were designed with climate science in mind. Three independent measurements of temperature and precipitation are made at each station, insuring continuity of record and maintenance of well-calibrated and highly accurate observations. The stations are placed in pristine environments expected to be free of development for many decades. Stations are monitored and maintained to high standards, and are calibrated on an annual basis.
The data is of high quality, so any new study looking for this effect may not even need to do the DTR averaging done by Dragić et al. to see the effect if it is real.
The logged USCRN data is now available online here http://www.ncdc.noaa.gov/crn/observations.htm The February Forbush decrease event I highlighted at the beginning of this post might make a good starting point.
I see a paper on this in the near future, maybe even in Dessler record time.
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Ok, thanks Leif.
GED. I put up some more charts.
I have 125 stations spread across the entire US. I updated my post and you can see the problem of having sunny days on the 19th
You can also cheery pick cloudy stations and see them brighten up after the 19th.
As you note there are many reasons why a cloudy station can stay cloudy and many reasons why it can get bright.
I suppose I could do something like this.
calculate the average daily insolation the week before and compare it with the average week insolation after..
Any bets gents
Leif S
The Diurnal Temperature Range is of no interest other than as an indirect way to measure cloudiness. Since we have no information what so ever about how DTR corresponds to cloudiness your guess is as good as mine. Maybe a +0.6 change in DTR corresponds to a big change in cloudiness, maybe it corresponds to a small change. Who knows?
You are trying to use Dragic result to rule out a significant effect on climate, but there is no way to do that. You can’t rule out a big effect and you can’t rule out a negligible effect. It goes both ways. The one important finding in this paper is that there IS an effect, which has been much debated since Svensmarks Forbush paper of 2009.
And of course we will see some results from CLOUD addressing some of these issues. And Kirkby will talk about them in due time, but he’ll better do the experiments and publish the results before telling us about them.
There is a bit of a logical impasse in some of the above posts.
Clouds are ALWAYS a result of temperature. Not absolute temperature but rather temperature differentials. Roy’s biderectional concept is therefore slightly misleading.
Clouds do not in themselves cause a temperature change but what they can do is alter the amount of solar energy that gets into the oceans to fuel the system.
So we need to consider what temperature changes cause cloudiness changes which then affect fuel for the system.
In my opinion such changes must occur within the vertical temperature profile of the entire atmosphere and that boils down to oceanic variability from below and solar variability from above both constantly competing to alter that vertical temperature profile.
Next we have to consider HOW the clouds can most effectively alter the fuel for the system AND tie that in with real world observations.
Simple seeding from more cosmic rays is not enough in my opinion because I know of no mechanism whereby changes in cosmic ray quantities can be observationally linked to the climate changes we have seen.
The changes we see are comprised primarily in changes to the positions and intensities of the established climate zones. They move poleward and equatorward cyclically over time and/or the mid latitude jets become more meridional or more zonal to change the speed of energy transfer from equator to poles.
Those changes can only be achieved via alterations to the vertical temperature profile and I see no evidence that cosmic rays do that.
Clouds are primarily a result of air mass mixing and temperature differentials developing between sea and the air above. When the mid latitude jets wave about more meridionally the air mass boundaries become much longer and total global cloudiness increases. When the air temperature tries to diverge from sea surface temperatures we see more sea fog or low stratus (the latter especially in tropical regions).
The opposite scenario applies when the jets behave in a more meridional fashion.
Observations suggest more zonality and less clouds when the system is warming and more meridionality and more clouds when the system is cooling.
The critical issue though is net solar energy uptake by the oceans which is obviously reduced to create a cooling system when there are more clouds.
We seem to have more clouds when the sun is less active but I don’t think it is anything to do with cloud seeding by cosmic rays because the temperature of the stratosphere and the height of the tropopause (and not cosmic rays) is what affects cloud amounts most effectively by changing the length of the air mass boundaries and so the amount of air mass mixing.
I think that is the simplest hypothesis capable of explaining what we see.
Steven Mosher–Don’t you have an event that occurs on a partly-cloudy day, so the process of cloud formation is ongoing? That would be a better basis for testing an hypothesis than starting out completely cloud-free.
Bengt A says:
September 12, 2011 at 3:20 pm
You can’t rule out a big effect and you can’t rule out a negligible effect. […]
The one important finding in this paper is that there IS an effect
‘IS” is a big words. They CLAIM there is an effect. The claim is not convincing.
Here are some other claims:
Kazil et al. (2006):
“the variation of ionization by galactic cosmic rays over the decadal solar cycle does not entail a response…that would explain observed variations in global cloud cover.”
Sloan and Wolfendale (2008):
“we estimate that less than 23%, at the 95% confidence level, of the 11-year cycle changes in the globally averaged cloud cover observed in solar cycle 22 is due to the change in the rate of ionization from the solar modulation of cosmic rays.”
Kristjansson et al. (2008):
“no statistically significant correlations were found between any of the four cloud parameters and GCR”
Calogovic et al. (2010):
“no response of global cloud cover to Forbush decreases at any altitude and latitude.”
Kulmala et al. (2010):
“galactic cosmic rays appear to play a minor role for atmospheric aerosol formation events, and so for the connected aerosol-climate effects as well.”
Excellent work. The current event should provide some live action confirmation.
But I must object to HankH’s comment: “Svensmark put fourth the theory that cosmic galactic rays (CGR) can produce cloud condensation nuclei” .
In fact, he put the theory forth first; there’s no evidence that he relegated it to fourth place.
>:-P
Brian H says:
September 12, 2011 at 5:42 pm
In fact, he put the theory forth first
Actually not. Ney did, back in 1959…
Steve (Mosh)
How about doing an analysis along the lines of Harrison and Stephenson 2006 ?
“Empirical evidence for a nonlinear effect of galactic cosmic rays on clouds”
doi: 10.1098/rspa.2005.1628 Proc. R. Soc. A
HS2006 studies data from several UK met sites, and it’d be good to see results for some US stations. You’ll need more data than Feb insolation though..
With respect to your question about latitudinal variations, there’s some information in the paper “Cosmic ray induced ionization in the atmosphere: Spatial and temporal changes” (Usoskin, Gladysheva and Kovaltsov 2004, DOI:10.1029/2004GL019507).
@Stephen Fisher Wilde says:
September 12, 2011 at 3:55 pm
“Clouds are ALWAYS a result of temperature. Not absolute temperature but rather temperature differentials.”
That is certainly true for precipitation, but the sign changes from summer to winter. A warming blast in winter makes it wetter, while in summer it takes a temperature drop to increase rainfall. So I guess the “was it the FD or the CME that made the clouds go away” study, is best looked at in summer months, with the reverse result expected for winter months.
I remember Nellie Forbush from “South Pacific”. Any relation?
RockyRoad says:
September 12, 2011 at 3:56 pm (Edit)
Steven Mosher–Don’t you have an event that occurs on a partly-cloudy day, so the process of cloud formation is ongoing? That would be a better basis for testing an hypothesis than starting out completely cloud-free.
########
For optimal detection I would think you would have to find those locations where it was somewhat ( how much) cloudy just prior to the event.
If you then saw:
1. No brightening, your observation disconfirms the theory
2. Brightening.. you have 1 more question:
was the brightening out of the ordinary.
Characterizing this is not simple.
In short: without Forbush events cloudy days give way to sunny days with a certain
frequency that is dependent on many factors. the Hypothesis would be that during these events that probablity goes up. That’s my current thinking on structuring an analytical approach.
Given a cloudy day whats the probablity ( with no Forbush) that you get a sunny day the following day, next day, next day etc. If Forbush effects the gensis of clouds that probablity structure would change.. supposedly.
Now I can just run off and calculate the average insolation in the week prior and the average in the week following and I can tell you that the effect is not found. That’s a weak test, but it indicates to me that first pass this theory will be hard to prove. If the effect was large, it would pop out of that test. It doesnt.
Leif may be able to help me with calculating the maximum insolation for any day at a given lat/lon.. that may give me a better handle on defining “cloudy”.. leif?
One universe:
Thanks that is the kind of measure i was looking for
“The ratio of diffuse to total solar radiation—the diffuse fraction (DF)—is used to infer cloud, and is compared with the daily mean neutron count rate measured at Climax, Colorado from 1951–2000, which provides a globally representative indicator of cosmic rays. ”
Now I just have to figure if I can get the DF
Steven Mosher says:
September 12, 2011 at 8:56 pm
Leif may be able to help me with calculating the maximum insolation for any day at a given lat/lon.. that may give me a better handle on defining “cloudy”.. leif?
The maximum insolation occurs as local [real solar] noon and depends on the zenith angle which is just the co-latitude of the station adjusted for solar declination:
http://en.wikipedia.org/wiki/Celestial_coordinate_system
http://pveducation.org/pvcdrom/properties-of-sunlight/elevation-angle
GIYF
Nope: cant get the DF.
Here is an example of yet another effect that didn’t hold up:
http://www.sciencemag.org/content/180/4082/185.short
“The solar magnetic sector structure appears to be related to the average area of high positive vorticity centers (low-pressure troughs) observed during winter in the Northern Hemisphere at the 300-millibar level. The average area of high vorticity decreases (low-pressure troughs become less intense) during a few days near the times at which sector boundaries are carried past the earth by the solar wind. The amplitude of the effect is about 10 percent.”
Leif S
Some of those papers you are listing are not even about Forbush decreases, and anyway they have no impact on the study by Dragic et al. You just seem to be in total denial of any cosmic ray-cloud interaction at all. Why don’t you read this comment by Jeff Pierce. He seems to think that Dragic et al has found something, but then again he’s only an expert:
http://www.realclimate.org/index.php/archives/2011/08/the-cerncloud-results-are-surprisingly-interesting/comment-page-4/#comment-214901
Steven Mosher says:
September 12, 2011 at 9:04 pm
Nope: cant get the DF.
Mosh, a guy who is interested in Milankovitch cycles has written a comprehensive program to calculate insolation at any point on earth at any epoch in the last few million years. You’ll need Matlab to run it though. Let me know if you want details.
Thanks TB I found a nasa fortran code to do it.. also some spatial maps.
need to get back to my other project
tallbloke, mosher, leif;
How fast are these major Forbush decreases supposed to have observable effects? Mosher’s thought regarding the week before vs the week after doesn’t sit well with me, there’s an awful lot of other factors that could be at play.
But what about night versus day? Since the coronal mass ejection in theory “sweeps away” in coming GCR’s, would the effect not be most pronounced on the night side of the planet? For that to be the case, the effects would have to be measurable in hours rather than days. If you were to use weather stations at high latitudes in winter just entering “night time” however, you could get 16+ hour windows. One would think that the largest Forbush decreases would have effects in that time window.
(my assumption here is that GCR do not as a rule go all the way through the planet unimpeded, and that there is a GCR deficity on the day side of the planet in the first place because the Sun would block from that side)
Bengt A says:
September 12, 2011 at 10:49 pm
Some of those papers you are listing are not even about Forbush decreases, and anyway they have no impact on the study by Dragic et al. You just seem to be in total denial of any cosmic ray-cloud interaction at all. […] He seems to think that Dragic et al has found something, but then again he’s only an expert
Suffice it to say that the cosmic ray – cloud interaction claims are not convincing to me. The current hype does not bite me as it must have you. I’m not trying to convince you about something, just telling you why I’m not convinced. As for expert, I do think that I have some expertise, having published sun-weather papers in journals like Science, Nature, and Journal of the Atmospheric Sciences link but, then again, I’m only a scientist.
davidmhoffer says:
September 13, 2011 at 12:30 am
(my assumption here is that GCR do not as a rule go all the way through the planet unimpeded
Galactic Cosmic Rays do not come from the Sun, but from the Galaxy [all around us] and do not penetrate the Earth at all.
Bengt A says:
September 12, 2011 at 10:49 pm
Some of those papers you are listing are not even about Forbush decreases, and anyway they have no impact on the study by Dragic et al.
Yet your ‘expert’ refers to one of them:
“This was discussed in the Calgovic 2010 FD paper http://www.agu.org/pubs/crossref/2010/2009GL041327.shtml ”
“Currently a cosmic ray cloud connection (CRC) hypothesis is subject of an intense controversial debate. It postulates that galactic cosmic rays (GCR) intruding the Earth’s atmosphere influence cloud cover. If correct it would have important consequences for our understanding of climate driving processes. Here we report on an alternative and stringent test of the CRC-hypothesis by searching for a possible influence of sudden GCR decreases (so-called Forbush decreases) on clouds. We find no response of global cloud cover to Forbush decreases at any altitude and latitude.”
Those people seems to be in complete denial. Or rather, they did what scientists do: looked at the claim and found it wanting.
@Mosher,
If the first pass, average insolution week before verses week after, shows no statistical difference, that definitely curretnly falsifies this hypothesis for this particular event. It is a weak test, yes, but if there was a significant difference we should see it, as you said. I suppose the event was beneath the stated percentage that this paper puts forth for being able to have an effect detectable above noise; but it’s so hard to say anything conclusive in any direction. I do wish we could figure out a stronger test, but if you can’t get the DF, what more can really be done? We’d have to do an analysis identical to this paper and check several Forbush’s of various magnitudes, then analyze their averages (based on total and based on class perhaps). But that’s a lot of work, as you’d be making a companion paper to theirs!
So then, I’m satisfied with the test you have done and saying, “this particular event on the 19th of February had no statistically significant effect on cloud coverage as done by a week prior/week after analysis.” And that this is not in agreement with the proposed hypothesis of a strong connection between GCR and cloud formation.
Leif S
The paper by Jasa Calogovic and Frank Arnold you’re citing isn’t very impressive. They chose to few and to weak FDs to be able to see any effect of cosmic rays on clouds. Hardly surprising they didn’t find any effect. Here’s Nigel Calder writing about their paper:
“At the risk of discourtesy to the distinguished authors, I can report that Svensmark laughed when he read the paper from Arnold’s group. Where his own team studied three different satellite data sets and 26 Forbush decreases, Arnold’s took just one data set (ISCCP) and only six events – those ranking 4th, 10th to 13th, and 26th, in Svensmark, Bondo and Svensmark’s assessment of effects on cosmic rays reaching the lower atmosphere. In the Danes’ plot of all their ISCCP results (see above) all but one of the Swiss-German selection have “strengths” between 33 % and 69 %, where any reduction in clouds is similar to the uncertainty. “Of course they couldn’t see anything,” Svensmark said to me.”
(source: http://calderup.wordpress.com/2010/05/03/do-clouds-disappear/)
Leif S
I hope I don’t misinterpret Jeff Pierce, but from his comments on realclimate it seems that he, at least in regard to the effect of FDs, somewhat has changed his opinion on the cosmic rays – cloud interaction.
“…I was an opponent at Torston Bondo’s (Svensmark’s student) PhD defense. I wanted to know what I was getting myself into, so I re-analyzed much of the data in the Svensmark paper and tweaked some of their assumptions including some of the issues raised in the RC post (e.g. randomly removed 1 or 2 of the “big 5″ events, changed their criteria for their minimum daily AERONET measurements, not used any temporal smoothing) and the results do not change greatly. I definitely think the jury is still out, but I also think the Svensmark paper caries weight…”
Se full comments here:
http://www.realclimate.org/index.php/archives/2011/08/the-cerncloud-results-are-surprisingly-interesting/
http://www.realclimate.org/index.php/archives/2011/08/the-cerncloud-results-are-surprisingly-interesting/
Does that mean they are getting heavy toothaches from it? ;p 😉
n. Soft decayed area in a tooth; progressive decay can lead to the death of the tooth